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At the highest metrological level, biogas standards are commonly prepared gravimetrically as PSMs (primary standard mixtures). This international key comparison addresses the composition of biogas, to support calibration and measurement services for this renewable energy gas. The mixtures contain nitrogen, carbon dioxide, methane, ethane, propane, hydrogen and oxygen and represent the composition of biogas from landfills. The results in this Track C key comparison on the composition of biogas are generally good. Some of the datasets, especially that of oxygen, showed substantial extra dispersion, that could not be explained by the stated uncertainties. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The remarkable relationship between the size, shape, and optical properties of silver nanoparticles is proving to be very useful in a range of high performance applications. Considerable effort and investment are focused on delivering silver nanoparticles with precise morphologies. However, the reliability of these particles is contingent upon the morphological stability, particularly against variations in the thermodynamic environment, such as changes in temperature. Using a combination of computational and theoretical approaches, we have constructed a size- and shape-dependent phase diagram of nanoscale silver and projected the optical emission spectrum to produce a detailed structure/property map at thermal equilibrium. This map demonstrates that faceted near-spherical shapes and spheres are the predominant morphologies in a Ag NPs colloidal sample at low and high temperatures, showing a light yellow color. However, samples with more faceted shapes such as cubes or tetrahedrons, which gain stability at...

Beranek J., Safrankova I. (2010): First Record of Horidiplosis ficifolii Harris 2003 (Diptera: Cecidomyiidae) in the Czech Republic. Plant Protect. Sci., 46: 189–191. In November 2009 the gall midge species Horidiplosis ficifolii Harris 2003 was detected in the Czech Republic on leaves of an ornamental fig Ficus microcarpa. The insect is native to South East Asia, where it lives on the genus Ficus. No information is currently available on the prevalence of the pest in the countries of its origin. Imported Ficus plants from China into the Netherlands are sometimes heavily infested with the gall midge. In Europe it is also known from Denmark and the United Kingdom. As Horidiplosis ficifolii is a tropical species, no environmental and social damage is expected.

Measurements of cloud condensation nuclei (CCN) concentrations, single particle composition and size distributions at a high-elevation research site from March 2011 are presented. The temporal evolution of detailed single particle composition is compared with changes in CCN activation on four days, two of which include new particle formation and growth events. Sulfate-containing particles dominated the single particle composition by number; biomass burning particles, sea salt particles, and particles containing organic components also were present. CCN activation largely followed the behavior of the sulfate-containing particle types; biomass burning particle types also likely contained hygroscopic material that impacted CCN activation. Newly formed particles also may contribute to CCN activation at higher supersaturation conditions. Derived aerosol hygroscopicity parameters from the size distribution and CCN concentration measurements are within the range of previous reports of remote continental kappa values.

Systematic analysis of pumping kinetics of iodine photodissociation laser was performed in a free running regime. For a practical example, the A 3 amplifier of the iodine laser system PERUN was placed inside a planar resonator and the output energy was calculated in dependence on the mixture composition and compared with the extractable energy in the amplifier case.

This document is part of Subvolume B ‘Laser Systems’, Part 1 of Volume 1 ‘Laser Physics and Applications’ of Landolt-Bornstein Group VIII ‘Advanced Materials and Technologies’.

Orofacial stimulation seems to be one of further possibilities of curing SAS. It is especially suitable in the case of mixed or central type of SAS [3, 4]. It may favourably influence some subjective complaints of the patients, but also the sleep profile and apnea index. The advantage of this method is that it does not stress the patient and may be used individually or in combination with CPAP [7] or surgical treatment [5]. In our country we have applied this method as the first in the treatment of snoring and SAS. We have not find this treatment of SAS in world literature.

A great number of patients suffering from SAS (19.5% according to our study) exhibit other complicating illnesses. This requires a complex diagnostic and therapeutic approach. Of these complicating illnesses the most frequent are neuropathy, thyreopathy and similar metabolic diseases. A polygraphic investigation alone may not suffice. It is necessary for a neurological specialist, acquainted with sleep disorders. This neurologist co-operates with the other specialists. A correctly indicated therapeutic procedure (conservative or surgical) will prevent a future relapse of the illness.

The EURAMET supplementary comparison EURAMET.QM-S9 involves standard gas mixtures of synthetic natural gas. It is similar to key comparison CCQM-K16 (2001-2002). Analysed were gas mixtures of synthetic natural gas containing nitrogen, carbon dioxide and the alkanes up to hexane with a total of 10 components. Four laboratories (CMI, Czech Republic; INMETRO, Brazil; SMU, Slovakia; and VSL, The Netherlands) participated in this supplementary comparison. All of the participants, except CMI, have established facilities for natural gas analysis, and have existing claims for their Calibration and Measurement Capabilities (CMCs) for natural gas mixtures. The agreement of the results in this supplementary comparison is very good. All the results with their reported uncertainties are in agreement with the reference values for all the participants. SMU and VSL participated in the key comparison CCQM-K16. VSL obtained very good results in both the supplementary comparison and the CCQM-K16 comparison. SMU obtained better results in the supplementary comparison than in CCQM-K16. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM.

The triangulation arrangement of one nitrogen and two oxygen atoms proposed as a requirement for antileukemic activity involving a "common receptor-complement feature" has been reevaluated specifically as it applies to nucleosides. This re-evaluation has resulted in a rejection of the "receptor-complement feature" as a working model for the a priori design of nucleosides as compounds active against leukemia L-1210.

Motion of the wavecrests is calculated for the case when a frequency modulation has been imposed locally on a coherent ionisation wave with saturated (large) amplitude. Different possibilities of continuation of the solution into the region of multivaluedness are discussed and compared with the experimentally observed pattern.

Treatment of adenosine with metaperiodate followed by condensation with nitromethane yielded a mixture or 3′-deoxy-3′-nitrohexopyranosyl adenines which were converted to 3′-amino-3′-deoxyhexopyranosyl nucleosides. Separation of this mixture followed by acetylation yielded three crystalline isomeric 9-(3′-acetamido-3′-deoxy-2′,4′, 6′-tri-O-acetyl-β-D-hexosyl)adenines which were proved by chemical and n. m. r. studies to be the manno (VII), gulacto (X) and gluco (XIII) derivatives.

A new species Torulopsis armenti Kockova-Kratochvilova, Slavikova et Beranek isolated from brain, liver, and kidney of cattle, which perished of a nervous disease, is described.

The stability of cyclocytidine (II) in aqueous solutions decreased with increasing pH and temperature. After intravenous injection to rats the biphasic decline of cyclocytidine in the serum was accompanied by simultaneous formation of arabinosylcytosine. Since under physiological conditions (37 degrees C, pH 7.2) the half-lifetime of cyclocytidine dissolved in water was 5 hours, the very early appearance of arabinosylcytosine in the serum of rats suggests that various hydrolytic enzymes may also be responsible for the conversion of cyclocytidine in to arabinosylcytosine in vivo. An equimolar dose of arabinosylcytosine (I) injected to rats produced serum levels which were several times higher than those of cyclocytidine under the same conditions. Since the rate constant of overall elimination was similar for both compounds, this difference in serum levels may most probably be explained by a much higher distribution volume of cyclocytidine resulting also in a higher plasmatic clearance of this compound.

A selected series of nucleoside analogues were tested for inhibitory activity vs DNA and/or RNA synthesis at L1210 cells. The structure-activity relationship was studied among derivatives of 5-fluorouracil and arabinosylcytosine (araC), compounds clinically used in cancer chemotherapy. 5-Fluorouridine was found to be a selective, most potent inhibitor of RNA synthesis. Arabinosylcytosine was the most potent selective inhibitor of DNA synthesis. Only cyclocytidine stands very close to the carcinostatic antibiotics in its strong simultaneous inhibition of both DNA and RNA synthesis. A biologically interesting new group of 5'-deoxy derivatives of arabinosylcytosine was investigated. The inhibitory activity vs DNA and/or RNA synthesis is compared with the activity against growth of E. coli and against herpes simplex virus type I (HSV). The system for inhibition of NA synthesis is proposed as a preliminary first step: an in vitro screening method promising for the discovery of new types of potential carcinostatic agents. Both transport and biotransformation processes of nucleoside analogues were studied in the isolated everted rat jejunum with a continuous perfusion technique. The 5'-substituted derivatives of araC and 5'-chloro-5-fluorouridine exhibited higher transport rates and higher metabolic stability during intestinal penetration than the parent nucleosides. There was found to be no correlation between lipophilicity and transport rate, but there is a correlation between lipophilicity and metabolic alterations among the nucleoside derivatives studied.

Eine direkte Synthese vonl- undd-Cycloserin ausl- undd-Serin wurde beschrieben. Die bakteriostatischen Effekte der drei Formen von Cycloserin (d-,l-unddl-) aufE. coli in synthetischem Medium wurden verglichen.

A construction and exploitation of a comparatively large I photodissociation laser system (Perun) is reported. This system was constructed in cooperation between the Institute of Physics of Czechoslovak Academy of Science in Prague and the Lebedev Institute of Physics of Soviet Academy of Science in Moscow. The laser produces subnanosecond pulses of maximum 50 J and 0·5 ns in duration. Although the pumping time by Xe flashlamps is long enough for an acoustic disturbance released in the active medium to introduce an optical inhomogeneity across the whole cross section of the laser tube, the radiation can be focused in a focal spot of a power density exceeding 1014 W/cm2, enough for meaningful laser target experiments both for a laser plasma production or a modification of solid surfaces. The repetition time of the shots is about 10 min.

A coherent ionization wave with large (saturated) amplitude which is modulated in frequency at z = 0 develops a discontinuity if (∂ 2 ω/∂ k 2 )(∂ω/∂ t ) > 0. This can be modelled by a cusp catastrophe using the time coordinate as control parameter.